JPH05307179A - Production of monomolecular film and production of monomolecular piled up film - Google Patents

Abstract

PURPOSE:To increase the bonding strength of molecules to a substrate and to obtain the monomolecular film oriented with the molecules oriented in the same direction by treating the surface of the substrate to impart reactivity thereto and bringing functional groups into reaction with the surface of the substrate by using the specific molecules. CONSTITUTION:The surface of the substrate 1 is treated, by that, the reactivity is imparted to a treated layer 2. The molecules 3 having the two functional groups at both ends of the rigid molecular skeleton having >=15 angstrom length are used and one of the two functional groups is brought into reaction with the surface of the substrate 1, by that, the monomolecular film of the first layer is formed. Further, the molecules 4 having the two functional groups at both ends of the rigid molecular skeleton having >=15 angstrom length are used and one of the two functional groups is brought into reaction with the other functional group of the molecules constituting the monomolecular film of the lower layer, by that, the monomolecular film of the upper layer is formed. The reason that the length in the longitudinal direction of the molecular skeleton is limited to >=15 angstrom lies in that the control of the molecule orientation on the substrate 1 is difficult if the length is below 15 angstrom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a monomolecular film and a method for producing a monomolecular cumulative film.

[0002]

2. Description of the Related Art Conventionally, the LB method has been known as an excellent method for producing a monomolecular film. In this method, a linear molecule having a hydrophilic group and a hydrophobic group is developed at a gas-liquid interface and compressed to generate a monomolecular film, and the monomolecular film is brought into contact with the substrate to form the monomolecular film on the substrate. To be transferred to. Further, by repeating the upper and lower sides of the substrate, the monomolecular film can be accumulated.

However, in the LB method, the monomolecular film is only physically adsorbed on the substrate, and its force is extremely weak.
The B film is a very weak film. Further, in the LB method, a clean room is required so as to prevent defects in the film due to dust and the like, and careful attention must be paid to cleaning and purification of the materials used.

Further, when forming a Y film by the LB method,
Since molecules are inverted when accumulating monomolecular films, it is not possible to obtain an accumulating film in which dipole moments are oriented in the same direction, for example. On the other hand, when forming the X film by the LB method, it is possible to control the molecular orientation, but it is actually difficult to form a perfect X film.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of producing a monomolecular film and a monomolecular cumulative film in which molecules have a strong binding force to a substrate and the molecules are oriented in the same direction. ..

[0006]

Means and Actions for Solving the Problems A method for producing a monomolecular film according to the present invention comprises a step of treating a surface of a substrate to give reactivity, and a step of applying a reactive molecular skeleton to both ends of a rigid molecular skeleton having a length of 15 angstroms or more. Using a molecule having at least one functional group, and reacting the functional group with the surface of the substrate.

The method for producing a monomolecular cumulative film of the present invention comprises a step of treating the surface of a substrate to give reactivity, and a molecule having two functional groups at both ends of a rigid molecular skeleton having a length of 15 angstroms or more. And a step of reacting one of the two functional groups with the surface of the substrate to form a monolayer of the first layer, and two functional groups at both ends of a rigid molecular skeleton having a length of 15 angstroms or more. Using a molecule having a group, and reacting one of the two functional groups with the other functional group of the molecule constituting the lower monolayer to form an upper monolayer. It is what

The method of the present invention will be described with reference to FIGS. 1 (a) to 1 (c). In addition, in FIG. 1, the functional groups in the molecule are represented by A to D.
Is displayed in. First, as shown in (a), the surface of the substrate 1 is treated to give reactivity to the treatment layer 2. next,
As shown in (b), the molecule 3 having the functional groups A and B is reacted at both ends of the rigid molecular skeleton to form a monolayer film of the first layer. When manufacturing a monolayer, the process ends at this stage. When producing a monomolecular cumulative film, as shown in (c), molecules 4 having functional groups C and D are reacted at both ends of a rigid molecular skeleton to form a second monolayer film. Further, if necessary, the operation (c) is repeated to produce a monomolecular cumulative film. Hereinafter, the present invention will be described in more detail.

In the present invention, substrates made of various materials can be used, and those having functional groups regularly and densely on the surface are suitable. The -OH group is the most common as such a functional group. -O
The H group can be easily generated by treating the surface of a substrate made of glass, silicon, germanium, metal or the like with an acid or the like. Therefore, considering that it is used by incorporating it into an electronic circuit as an element,
A substrate on which a conductive metal thin film is formed by vacuum vapor deposition of Al or sputtering of Au on an arbitrary substrate surface can be used as the substrate. When these metals are used, active points may be generated by, for example, irradiating the surface with a high energy beam.

However, for example, --OH on the surface of Si
It is known that the groups are present only at a density of 1 per 20 square Angstroms (Z. anor
g. allg. Chem. , 389, 92 (197
2)). Therefore, it is considered that packing is not sufficient even if an attempt is made to react the -OH group with the functional group of the organic molecule to form a monomolecular film.

Therefore, it is preferable to further treat the surface of the substrate to make it reactive, that is, to make the functional groups on the surface of the substrate more dense. In the present invention, the following various methods can be used to treat the surface of the substrate to make it reactive.

For example, after treating the substrate as described above with an acid to generate --OH groups, the surface of the substrate is treated with silicon tetrachloride or a silane coupling agent such as trialkoxysilane or tetraalkoxysilane. To do. Among these, trialkoxysilane and tetraalkoxysilane, which do not generate hydrogen chloride by the reaction, are more preferable. Further, an isocyanate compound having two or more isocyanate groups (tetraisocyanate silane, hexamethylene diisocyanate, p-diisocyanate benzene, etc.) or an isothiocyanate group is 2
You may use the isothiocyanate compound which has three or more. When these compounds are used, the protective group may be removed after the functional group is partially protected and reacted with the substrate.

Incidentally, among the tetraalkoxysilanes used as the surface treatment agent, the conventionally used concentrations of 2 to 5 are used.
When the substrate is treated with a wt% tetraethoxysilane aqueous solution, there is a problem that it takes a long time of 24 hours or more to sufficiently treat the substrate surface and generate functional groups at a high density. Generally, if the concentration of the surface treatment agent is increased, the treatment time of the substrate can be shortened, but if the concentration of the tetraethoxysilane aqueous solution is increased, the self-polymerization may occur and the fluidity may be lost, and the substrate may not be used.

Therefore, in the present invention, it is preferable to use a solution prepared by dissolving tetramethoxysilane in a mixed solution of water and an organic solvent such as acetone. An organic solvent such as acetone has a function of improving the solubility of tetramethoxysilane. In addition, it is preferable to adjust the pH by adding an acid such as acetic acid to this solution. The concentration of tetramethoxysilane in the solution is preferably 20 wt% or more. The reason for this is that if it is less than 20 wt%, the reaction is slow and the treatment time becomes long to increase the density of the functional groups. At a concentration of 20 wt% or more, the self-polymerization of tetramethoxysilane is promoted to some extent, but the treatment time can be shortened. The higher the concentration, the shorter the processing time. However, the higher the concentration, the more easily self-polymerization occurs in a short time, so it is preferable to process a large amount of substrates at one time. Further, at a concentration of 50 wt% or more, self-polymerization occurs even by giving a slight vibration, so the concentration is 20 to 50 wt%, and further 20 to 30 w.
The range of t% is more preferable. Further, the pH of the tetramethoxysilane solution is preferably 4 or less. If the pH is above 4, especially above 5, the reaction will be slow.

Further, an organic material such as a polymer or a polymer precursor may be formed on the surface of the substrate in order to impart reactivity to the surface of the substrate. Examples of the polymer include polyvinyl alcohol, polyvinyl phenol, and phenol resin as a polymer having a —OH group as a functional group, and an epoxy resin as a polymer having an epoxy group. A specific method of forming a polymer is a method of applying the above-mentioned polymer or a precursor thereof to the surface of a substrate, a method of applying a polymer having active sites arranged at equal intervals such as polybisacetylene to the surface of a substrate, and a functional group. A method of epitaxially growing a diacetylene compound or bis-olefin compound possessed on a substrate and photoreacting this to form a polymer in which active points are arranged at equal intervals, and irradiating the polymer formed on the substrate surface with a high energy beam Depending on the method, a method of generating active sites can be mentioned. Further, these polymers themselves may be used as the substrate. As described above, in the present invention, a substrate having at least a surface made of a polymer can be used, so that the degree of freedom in selecting a substrate is greatly expanded.

In the present invention, the rigid molecular skeleton in the molecules constituting the monolayer has a length in the longitudinal direction of 15 angstroms or more. The reason why the length of the molecular skeleton in the longitudinal direction is limited to 15 angstroms or more is that if it is less than this, it is difficult to control the molecular orientation on the substrate. Here, the rigid molecular skeleton means a portion in which the bond angle and the length of the skeleton do not change due to free rotation of the bond, and for example, in the case of having a functional group containing a freely rotatable bond, The part is not included. The length of the rigid molecular skeleton in the longitudinal direction is preferably 50 angstroms or more, and more preferably 100 angstroms or more. It is desirable that the rigid molecular skeleton occupy 80% or more in the longitudinal direction of the molecule, and the larger the better.

Examples of rigid molecular skeletons are ring structures such as 5-membered or 6-membered aromatic rings, hydrocarbon rings, hetero rings or condensed rings thereof, which correspond to mesogens of liquid crystal molecules, or these. Examples include those that are linearly linked. Examples of the binding site include a Schiff base bond, an ester bond, a diazo bond, a carbon-carbon double bond and a carbon-carbon triple bond.

Specifically, as a ring structure and a binding site which are components of a rigid molecular skeleton, biphenyl, triphenyl, bipyridine, bipyrazine, phenylpyrimidine, phenylpyridazine, benzene, pyridine, pyridazine, pyrimidine, pyrazine and triazine are provided. , Tetrazine, 1,4-dioxazine, 1,4-thiazine, thienothiophene, benzofuran, 2,3-dihydrobenzofuran, furan, oxolane, 1,3-dioxolane, thiolane, pyrrolidine, 2-pyrazoline, pyrazolidine,
2-imidazoline, oxane, 1,4-dioxane, thiane, piperidine, 1,4-dithiane, piperidine, piperazine, pyrrole, thiophene, pyrazole, imidazole, triazole, 1H, 1,2,4-triazole, 1H-tetrazole, Isoxazole, oxazole, furazan, isothiazole, thiazole, 2H-
Pyran, 4H-pyran, benzothiophene, indole, indoline, isoindole, isoindoline, isoindolizine, 1H-indazole, 2H-indazole, benzimidazole, benzotriazole, benzooxadiazole, benzothiazole, benzothiazoline, purine, 2H-chromene, 4H-chromene, chroman, isochroman, quinoline, isoquinoline, 4H-
Isoquinoline, 4H-quinolidine, cinnoline, quinazoline, quinoxaline, phthalazine, 1,8-naphthyridine, pteridine, dibenzofurancarbazole, xanthene, dibenzothiopyran, acridine, thianthrene, phenazine, phenoxine, phenoxazine, phenothiazine, phenanthridine, phenanthrene. ,
1,10-phenanthrylone, phenazone, pyrene, naphthalene, quinuclidine, polypyrrole, poly (N-substituted pyrrole), poly (3,4-disubstituted pyrrole), polythiophene, poly (3-substituted thiophene), polyaniline, polypyridine , Polyazulene, polyvinylcarbazole, polyselenophene, poly (N-substituted carbazole), polyfuran, poly (2,5-furylenevinylene), polybenzothiophene, poly (phenylenevinylene), poly (2,5-thienylenevinylene) ), Polybenzofuran, poly (paraphenylene), polyindole,
Examples include polyisothionaphthene, polypyridazine, polyacetylene, and polydiacetylenes.

Examples of rigid molecular skeletons include steroid skeletons, porphyrin skeletons, polyamides, proteins, sugars, cyclodextrins, nucleic acids and DNAs. Of these, polyamide means one having a monomer unit capable of forming a higher-order structure, and includes an oligomer. A typical example of the polyamide is a polyamino acid which alone forms an α-helix structure. The α-helix structure is very rigid because it is maintained by hydrogen bonding. For example, polyalanine, polyaspartic acid ester, polyglutamic acid, polyglutamic acid ester,
Examples include polyleucine, polylysine, polyphenylalanine, and polytyrosine. Further, a polyamino acid which alone does not form an α-helix structure may be used in combination with a polyamino acid which alone forms an α-helix structure. Examples of such polyamino acids include polyvaline, polyisoleucine, polyacetylserine, polyserine, and polys-.
Methyl cysteine, poly o-acetyl threonine, poly threonine, polyproline, etc. are mentioned.

In the present invention, the functional group which reacts with the surface of the substrate in the molecule constituting the first layer monomolecular film formed on the surface of the substrate causes a desired reaction depending on the treatment of the substrate described above. Is selected as appropriate.

For example, as the functional group which reacts with the metal on the surface of the substrate, an acid group such as --COOH group, --OH group,
Examples thereof include halogen. Regarding the bond between the substrate and the molecule constituting the monomolecular film, a salt is formed when the —COOH group is used, an alkoxy bond is formed when the —OH group is used, and a halogen is used when the —OH group is used. Form an organometallic bond. Further, the silane coupling agent reacted on the surface of the substrate, to be exact, the functional groups that react with the hydroxysilane derived from the silane coupling agent include -OH group, -COOH group,
-NH ₂ group, a halogen, -CHO group, -COOCl group,
Examples thereof include sulfonic acid group, -SH group, epoxy group, active moiety of Grignard reagent, ylide, benzyne, isocyanate group, isothiocyanate group and the like. In addition, examples of the functional group that reacts with the precursor of the epoxy resin applied to the surface of the substrate include an amino group and a hydroxyl group. In this case, they are reacted with a curing agent to cause polymerization at the same time.

The other functional group in the molecule constituting the monomolecular film is not particularly limited. When producing a monolayer, the other functional group need not be reactive. When producing a monomolecular cumulative film, the other functional group is appropriately selected according to the functional groups of the molecules constituting the second layer monomolecular film. In this case, it is also possible to remove the protective group after the other functional group is protected and reacted with the surface of the substrate. further,
Similarly, the functional groups of the molecules constituting the monolayers of the second and subsequent layers are appropriately selected. In addition, as will be described later, molecules having various functional groups are selected according to the characteristics required in the device to which it is applied.

By using the method of the present invention, a monomolecular film can be formed on a substrate whose surface is made of a polymer, as described above. Here, at the molecular level, the surface of the polymer has numerous voids and the arrangement of polymer molecules is not a dense network, so it is considered that the polymer has a structure with extremely large undulations. Even if an LB film is formed on such a surface and molecular alignment is attempted by physical adsorption, the adhesion between the substrate and the film is not uniform, so that the film cannot be actually formed. On the other hand, in the present invention, since molecules are chemically reacted with the surface of the substrate and fixed by chemical bonds, film formation is possible. Therefore, when sufficient reaction conditions are set, a strong film can be formed.

Further, by treating the polymer molecules on the surface of the substrate, the smoothness of the substrate can be improved and the above object can be easily achieved. For example, materials such as tetramethoxysilane and tetraethoxysilane, which are silane coupling agents, fill the gaps between polymer molecules, and these materials themselves form a new silane polymer network layer, so the effect of smoothing the surface is expected. it can. The new silane polymer network formed in the uppermost layer is in equilibrium with Si (OH) ₄ in the solution, and the portion protruding from the plane is detached, so that a smooth surface is always present. That is, when the reaction is stopped, a flat surface of a certain number of layers of silane polymer is obtained.

A more effective method of forming a monomolecular film on a polymer plane as described above is to react macromolecules sufficiently large with respect to the roughness of the plane. As a result, if the planar roughness can be neglected, a monomolecular film can be formed even on a polymer having a rough surface. To this end, the effectiveness is further increased by using a surface treatment agent having a structure having a spacer having a sufficient length in the normal direction. It is considered that such a spacer has appropriate flexibility and has a function of arranging target molecules on the ideal plane of the substrate. Furthermore, by combining the above-mentioned actions, effective control of the molecular arrangement can be achieved even on the polymer substrate.

Further, in the case of forming a monomolecular cumulative film, if tetraalkoxysilane or trialkoxysilane is used between the steps of repeatedly forming the monomolecular film as described above, the surface of the lower monomolecular film can be formed. The functional groups can be more dense. In this case, a -O-Si-O- layer exists between the upper and lower monomolecular films. Note that instead of using such a tetraalkoxysilane or trialkoxysilane for the surface treatment of the substrate, the substrate is immersed in a solution of the reaction product after the reaction with the functional groups of the molecules forming the monomolecular film in advance. Also, it is possible to form a monomolecular film in exactly the same manner.

In the present invention, when the substrate is submerged in a reaction solution containing a molecule having at least one functional group at both ends of a rigid molecular skeleton and the functional group is reacted with the surface of the substrate, the substrate is submerged. The speed is preferably 10 cm / min or less. Substrate sink rate is 10 cm / min
When it exceeds, it becomes difficult to obtain a desired orientation. Further, it is more preferable to set the rate of submerging the substrate in the reaction solution to 4 cm / min or less because diffusion of the reaction solution is suppressed.

The molecular skeleton of the molecules constituting the monomolecular film formed by the method of the present invention is inflexible and has planarity. When such molecular skeletons overlap each other, the free energy becomes low and a crystalline molecular group is formed.
Therefore, if a monomolecular film is formed on the surface of the substrate by the method of the present invention, a molecular group corresponding to a bulk crystal having a strong binding force with the substrate and having high orientation can be formed. Can be aligned in the normal direction. Such a monolayer is a waveguide of a non-linear optical element such as SHG or THG; photoconductivity is imparted by the orientation of a side chain coloring group; and an optical information recording material and a living body by introducing a photochromic group into the side chain. Various applications are conceivable such as application to light control of materials; notch filter using cholesteric liquid crystallinity; application to molecular device by fixing coloring group.

The molecules used in the monomolecular film and monomolecular cumulative film of the present invention differ depending on the device to which they are applied. For example,
When applied to a non-linear optical element that generates a second harmonic, a monomolecular film is formed on both ends of the π electron system,
An electron withdrawing group such as a cyano group, a nitro group, an ester group, a ketone group or a carboxylic acid group, an amino group, a substituted amino group,
A molecule in which an electron-donating group such as an alkoxyl group is present is used. It should be noted that these may be those having central symmetry and being inactive in the SHG in a crystalline state, as long as they are molecules having a large supramolecular polarizability β. When applied to an EL device, a molecule such as an aluminum quinoline complex having a suitable functional group, 2,5-bisstyrylpyrazine, or 2,6-bis [2- (1-naphthyl) vinyl] pyridine is used. Be done. When applied to a photoconductive material, dyes and pigments such as azos, bisazos, phthalocyanines, and naphthalocyanines having appropriate functional groups are used.

Further, by using the method of the present invention, a device having a relatively complicated structure can be manufactured. For example, in a non-linear optical element, in order to obtain the second harmonic with high efficiency, the phase matching between the incident wave and the harmonic becomes important. However, it is impossible to satisfy the perfect phase matching condition.
Therefore, implementation of quasi-phase matching using an inversion domain structure has been studied. The inversion domain structure is a structure in which the sign of the nonlinear polarization wave generated is alternately inverted for each periodically formed domain. In such a structure, the outputs of the second harmonics are superimposed on each domain, so that apparent phase matching can be realized. Conventionally, a waveguide having an inverted domain structure is formed of an inorganic material. On the other hand, a technique for forming an inverted domain structure in which the orientation of molecules is controlled using a monomolecular film of an organic material has not been established. For example, with the LB method, it is extremely difficult in principle to form an inversion domain structure.

In the method of the present invention, the step of selectively treating the first region of the substrate surface with the first surface treating agent to give reactivity, and the C-terminal of the polyamide is treated with the first surface treating agent. A step of reacting with a functional group to form a monomolecular film on the substrate, and a second region other than the first region on the substrate surface is selectively treated with a second surface treatment agent to give reactivity. By the step and the step of reacting the N-terminal of the polyamide with the functional group of the second surface treatment agent to form a monomolecular film on the substrate, a nonlinear optical element having an inverted domain structure can be manufactured.

Also, a step of selectively treating the first region of the substrate surface with the first surface treating agent to give reactivity, and reacting the C-terminal of the polyamide with the functional group of the first surface treating agent. And a step of forming a lower monolayer on the substrate, and a step of reacting the C terminus of the polyamide with the N terminus of the polyamide constituting the lower monolayer to form an upper monolayer. And a step of selectively treating the second region other than the first region on the surface of the substrate with a second surface treatment agent to give reactivity, and the N-terminal of the polyamide is treated with the second region.
Of forming the lower monolayer on the substrate by reacting with the functional group of the surface treating agent, and by reacting the N-terminal of the polyamide with the C-terminal of the polyamide constituting the lower monolayer. By repeating the operation of forming a molecular film, a nonlinear optical element having an inversion domain structure with the cumulative film as a constituent element can be manufactured.

In this case, in order to define the first region selectively treated with the first surface treatment agent on the substrate surface, a mask is formed in a region other than the first region (second region). A method is used. Specifically, a method of forming a photoresist pattern, a method of adhering an elastic body or the like, a method of using a printing technique such as silk screen printing, and the like are used as in the case of manufacturing a normal semiconductor device. Further, in order to define the second region on the surface of the substrate which is selectively treated with the second surface treatment agent, the mask is removed to newly expose the second region. The first and second regions are generally formed so as to form a stripe pattern.

First used to treat a substrate surface
As the second surface treatment agent, a silane coupling agent having a functional group, a titanium coupling agent, or the like is preferable. When such a coupling agent is used, the alkoxy group present in the coupling agent reacts with the substrate, and the functional group reacts with the C terminal or N terminal of the polyamide.
Examples of compounds that react with the C-terminal of polyamide include silane coupling agents having a primary amino group. As the one that reacts with the N-terminal of polyamide, for example, an isocyanate group, an isothiocyanate group, or
The silane coupling agent which has a COOH group is mentioned. These coupling agents may be used alone,
You may use it in combination.

More specifically, first, a mask is formed on the surface of the substrate, and desired regions are exposed and selectively treated with a surface treating agent to give reactivity to the C-terminal or N-terminal of the polyamide. Next, the C-terminal or N-terminal of the polyamide is reacted with the functional group of the surface treatment agent to form a monomolecular film on the substrate. Further, the mask is removed, and the exposed area is selectively treated with a surface treatment agent to give reactivity to the N-terminus or C-terminus of the polyamide. Next, the N-terminal or C-terminal of the same type of polyamide is reacted with the functional group of the surface treatment agent to form a monomolecular film on the substrate.

When forming a multilayer film, the C-terminal or N-terminal of the polyamide (same or different kind as the lower polyamide) reacts with the N-terminal or C-terminal of the lower polyamide in the first and second regions, respectively. Then, the operation of forming the upper monolayer is repeated. The polyamide constituting the upper monolayer is the same in the first region and the second region.

When a polyamide monomolecular film is formed on the surface of a substrate by such a method, a method for forming a substrate while forming a group of molecules corresponding to a bulk crystal having a strong binding force with the substrate and high orientation. The dipole moment can be aligned in the line direction, and an inverted domain structure can be formed. Therefore, in the nonlinear optical element having the waveguide made of such a monomolecular film, the second harmonic can be obtained with high efficiency.

[0038]

Embodiments of the present invention will be described below with reference to the drawings. [Example 1]

A 100-nm-thick Al film was vapor-deposited on the surface of a 5 mm-thick substrate made of a salt crystal to treat the substrate. Also, a 0.2 mol / l solution was prepared by dissolving 4-cyano-4'-hydroxytriphenyl in a dry dichloromethane / acetone (100: 25) mixed solvent.

The substrate was vertically submerged in the solution at a rate of 4 mm / min using a dip coater at 0 ° C. under a nitrogen stream. After leaving in this state for 6 hours, the substrate was pulled up, washed with acetone, and dried as it was.

When IR spectrum of this substrate was measured, absorption due to stretching vibration of CN was observed at 2025 cm ^-1 . From this, it is presumed that the molecule is bound to the substrate via an alkoxy bond.

With respect to the obtained substrate, SHG was measured by the device shown in FIG. In FIG. 2, a sample 21 is set on a rotatable sample stage 15. The laser light (wavelength 1064 nm) emitted from the YAG laser 11 that is reflected on the incident surface of the prism 12 is converted into a fundamental wavelength signal by the photodiode 13 and input to the digital oscilloscope 20. YAG laser 11
The laser light emitted from the laser light that has passed through the prism 12 is incident on the sample 21 from the monomolecular film side through the lens 14. The transmitted light from the sample 21 is reflected by the lens 16,
It is incident on the spectroscope 18 via the IR cut filter 17, and the second harmonic having a wavelength of 532 nm is dispersed. The second harmonic is converted into a detection wavelength signal by the photomultiplier tube 19 and input to the digital oscilloscope 20.

Using this apparatus, the position at which the SHG intensity at a wavelength of 532 nm was maximized was examined while rotating the sample stage 15. In this case, the maximum SHG light was observed for the light incident at an angle of about 15 degrees with respect to the surface of the sample 21. However, SHG light sufficient to measure the intensity was not obtained. Since SHG light was observed, 4
It was confirmed that the cyano groups of -cyano-4'-hydroxytriphenyl were oriented in the same direction. From these facts, it can be concluded that this molecule forms a monolayer. Since the maximum SHG light is observed when light is incident on the surface of the sample 21 at a certain angle, it is estimated that the molecules are slightly tilted.

From the above, it was confirmed that the method of the present invention can be a means for forming a non-linear optical element. Further, there is a possibility that a waveguide can be formed by selectively forming a monomolecular film on the substrate. [Example 2]

A film having a thickness of 1 is formed on the surface of a Colts substrate having a thickness of 2 mm.
The substrate was processed by depositing Al of 00 nm. Then, in the same manner as in Example 1, the first-layer monomolecular film made of 4,4′-dihydroxytriphenyl, the second-layer monomolecular film made of 4,4′-triphenylsulfonyl chloride, and 4-
A third-layer monomolecular film made of cyano-4'-hydroxytriphenyl was sequentially formed. The SHG of this sample was measured using the same apparatus as used in Example 1, and it was confirmed that the sample had SHG activity.

As a result of measuring the electron diffraction of this sample, a pattern of symmetry, which is considered to be derived from the ab plane when the molecular axis direction is the c axis, is observed, and the molecules are bonded almost perpendicularly to the substrate. It was estimated that [Example 3]

A well-washed preparation glass was reacted with silicon tetrachloride for surface treatment. By this surface treatment, it is expected that the functional groups of silicon-chlorine are exposed at a high density on the surface and the functional groups are oriented in the normal direction. This was immersed in a dry methylene chloride solution of 4-cyano-4'-hydroxytriphenyl to form a monomolecular film in the same manner as in Example 1. The SHG of this sample was measured using the same apparatus as used in Example 1, and it was confirmed that the sample had SHG activity.

As a result of measuring electron beam diffraction of this sample, a pattern of symmetry, which is considered to be derived from the ab plane when the molecular axis direction is the c axis, is observed, and the molecules are bonded almost perpendicularly to the substrate. It was estimated that

Further, a preparation glass treated with silicon tetrachloride was sequentially reacted with 4,4'-dihydroxytriphenyl and 4,4'-triphenylsulfonyl chloride to prepare a six-layer monomolecular cumulative film. As a result of measuring the electron diffraction of this sample, it was confirmed that the film was uniform. [Example 4]

A Si-ATR prism was prepared as a substrate, washed with a stream of distilled water for 1 hour, ultrasonically washed with methylene chloride for 5 minutes, and vapor-cleaned with Freon. In addition, 25 cc of distilled water and 1 cc of acetic acid were added to N- (2-aminoethyl).
-3-Aminopropylmethyldimethoxysilane (a silane coupling agent manufactured by Toshiba Silicone Co., Ltd., trade name TSL-8
345) 1.25 g were mixed and stirred to prepare a surface treatment liquid having a pH of 4. The Si-ATR prism was soaked in the surface treatment solution in a half area, left at room temperature for 2 hours, washed with acetone, distilled water and acetone in this order and dried.

On the other hand, 2 g of lithocholic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 25 cc of dry THF (tetrahydrofuran) and kept at 0 ° C., 1.4 g of DCC (dicyclohexylcarbodiimide) was added and reacted for 15 minutes. Since lithocholic acid has a cholesterol skeleton, it is rigid and cannot be bent by free rotation of bonds.
According to the molecular model, the longitudinal length of lithocholic acid is 1
It is 5 angstroms or more. The surface-treated Si-ATR prism was immersed in this reaction solution at a speed of 2 cm / min. The temperature of this solution was slowly raised to room temperature and allowed to react for 1 hour. After completion of the reaction, the reaction product was washed with acetone and water to remove by-products and excess lithocholic acid.

Observation of the half monomolecular film region of the Si-ATR prism by the ATR method revealed that
The absorption of NH was confirmed at 1510 cm ^-1 . Further, when observed using a polarizing plate, a large angle dependence was recognized, and it was confirmed that the orientation was high.

Further, water was dropped on each of two regions of the Si-ATR prism to measure the contact angle.
As a result, the contact angle was 41 degrees in the region where the monolayer was not formed and 54.5 degrees in the region where the monolayer of lithocholic acid was formed. It was found that the area was very hydrophobic.

For comparison, a monomolecular film was formed by setting the Si-ATR prism in the reaction solution at a rate of 10 cm / min or more. When the contact angle was measured in the same manner as described above, it was found that the contact angle did not exceed 45 degrees and the degree of hydrophobization was small.

Further, the treatment with the silane coupling agent and the reaction with the lithocholic acid reaction solution were repeated to form a monomolecular cumulative film. As a result, even if the number of layers exceeded 20 layers, a uniform film which was completely the same as the initial state was obtained. It was

On the other hand, when a monomolecular cumulative film is formed at a rate of submerging the Si-ATR prism in the reaction solution at 10 cm / min or more, defects tend to occur in the film from the fourth layer, and the results of observation by STM are shown. From this, it was found that the uniformity of the film was poor. [Example 5]

Prepare a slide glass as a substrate,
It was washed with a stream of distilled water for 1 hour, ultrasonically washed with acetone for 5 minutes, and steamed with Freon. Then, half the area of the prepared glass was surface-treated in exactly the same manner as in Example 4.

Next, the same reaction solution as used in Example 4 was treated with the surface-treated preparation glass at 4 cm / mi.
Sunk at a rate of n. The temperature of this solution was slowly raised to room temperature and allowed to react for 1 hour. After the reaction,
It was washed with acetone, water to remove by-products and excess lithocholic acid.

TN liquid crystal (manufactured by Merck Japan Ltd., trade name TE-T515) was dropped on the obtained monomolecular film, and a glass substrate on which a polyimide rubbing film was previously formed was placed on this. Further, these two surfaces were sandwiched between two polarizing plates and irradiated with light from a fluorescent lamp for observation. As a result, uniform normally white was observed in the crossed Nicols state, and it was confirmed that the monomolecular film on the surface of the prepared glass had an orientation control ability. It has been confirmed that the prepared glass that has not been processed or has been subjected to only silane coupling has no such orientation control ability.

For comparison, a monomolecular film was formed by immersing the prepared glass in the reaction solution at a speed of 10 cm / min or more. When the orientation controllability of the TN liquid crystal was examined in the same manner as described above, normally white was observed in the crossed Nicols state, but it was found that the brightness was poor and the uniformity was lacking.

Further, the treatment with the silane coupling agent and the reaction with the lithocholic acid reaction solution were repeated to form a five-layer monomolecular cumulative film. When the thickness of this monomolecular cumulative film was measured by ellipsometry, it was over 120 Å. Further, when the alignment ability of the liquid crystal molecules was examined in the same manner as above, the same result as above was obtained. [Example 6] A Si-ATR prism was prepared as a substrate, and a cleaning treatment and a treatment with a silane coupling agent were performed in the same manner as in Example 4.

On the other hand, poly-L-glutamic acid-γ-benzyl ester (PBL) was added to 50 cc of dry m-cresol.
G, Sigma Co., molecular weight 150,000) 3 g was dissolved and kept at 0 ° C., and DCC (dicyclohexylcarbodiimide)
1.4 g was added and reacted for 20 minutes. A surface-treated Si-ATR prism was immersed in this solution, the temperature of this solution was slowly raised to room temperature, and the reaction was allowed to proceed overnight. After the reaction was completed, the reaction product was washed with acetone and water to remove by-products and excess PBLG. The film thickness of the monomolecular film formed in this way is estimated to be about 100 nm, assuming that all the molecules stand perpendicular to the substrate surface.

Observation of the half monomolecular film region of the Si-ATR prism by the ATR method revealed that
Absorption of amidocarbonyl could be confirmed at 1630 cm ^-1 . Further, when observed using a polarizing plate, a large angle dependence was recognized, and it was confirmed that the orientation was high.

Further, water was dropped on each of the two regions of each half of the Si-ATR prism, and the contact angle was measured.
As a result, the contact angle is 22 degrees in the region where the monomolecular film is not formed and 54.5 degrees in the region where the PBLG monomolecular film is formed, and this region is due to the molecular skeleton of PBLG. It turned out to be very hydrophobic.

Also, using aluminum as the substrate, a PBLG monomolecular film was formed in exactly the same manner as described above. X
When the coverage of the substrate surface was measured by the PS method, the coverage of the surface was lower than when using a Si-ATR prism as the substrate, but N atoms were confirmed, and the ratio of C to N was 12: 1. It was in agreement with the composition ratio of.

A PBLG monomolecular film was formed in exactly the same manner as above, using prepared glass as the substrate. SHG of this sample was measured by the device shown in FIG. While rotating the sample stage 15, a wavelength of 5
The position where the SHG intensity at 32 nm was maximum was investigated. In this case, the maximum SHG light was observed in the light incident from the angle of about 65 degrees with respect to the surface of the sample 21. Since the SHG light was observed, it was confirmed that the PBLGs were oriented in the same direction.

Further, using a Si-ATR prism, aluminum and prepared glass as the substrate, the treatment with the silane coupling agent and the PB were performed in the same manner as described above.
The reaction with the LG reaction solution was repeated to form a monomolecular cumulative film. When the same measurement as described above was performed on these samples, SHG light was observed similarly to the above, and it was confirmed that the PBLGs were oriented in the same direction. Further, among these, the SHG characteristic diagram of the monomolecular cumulative film formed on the prepared glass is shown in FIG. As shown in FIG. 3, in this case, the maximum SHG light was observed at an angle of about 65 to 70 degrees with respect to the incident light. This is the PBL
This indicates that the orientation is stronger than that of the G monolayer. [Example 7]

A Colts substrate was prepared as a substrate, washed with methylene chloride and acetone, and water was added dropwise to measure the contact angle, which was 62 degrees. Then, in a mixed solvent of acetone: water = 20: 50, tetraethoxysilane (a silane coupling agent manufactured by Toshiba Silicone Co., Ltd., trade name TSL) is used.
-8124) was added and stirred to prepare a 5 wt% tetraethoxysilane solution having a pH of 3. After that, the surface of the substrate was treated with this solution for 1 hour and the contact angle was measured. The contact angle was 22 degrees, and the surface of the substrate was very hydrophilic. From this result, it can be seen that the substrate surface-
Although the OH group density was low, it was confirmed that the —OH group density on the substrate surface was remarkably increased by the treatment with tetraalkoxysilane.

Then, the substrate surface-treated with tetraethoxysilane as described above was further surface-treated with the same surface treatment solution as in Example 4, and then the same reaction solution as that in Example 4 was used. Upon immersion, a monolayer of lithocholic acid could be formed as in Example 4. [Example 8]

Prepared glass was prepared as a substrate. The contact angle of this prepared glass with water was 6 degrees. This was washed with a stream of distilled water for 1 hour, ultrasonically washed with methylene chloride for 5 minutes, and steam washed with Freon. On this, polyvinyl alcohol was spin-coated to a thickness of 0.1 μm and dried to obtain a substrate whose surface was made of a polymer having —OH groups.

Further, 25 cc of distilled water and 1 cc of acetic acid were mixed with 1.25 g of a silane coupling agent having an amino group (Toshiba Silicone Co., Ltd., trade name TSL-8345), and the mixture was stirred to give a surface treatment solution of pH 4. Was prepared. The substrate was dipped in this surface treatment solution, allowed to stand at room temperature for 24 hours, washed with acetone, distilled water and acetone in this order and dried.

On the other hand, methylene chloride has a molecular weight of 51,000.
Poly-L-glutamic acid γ-benzyl ester (PB
3g of LG, Sigma) is melted and kept at 0 ° C, DC
0.1 g of C (dicyclohexylcarbodiimide) was added and reacted for 15 minutes. The surface-treated substrate was immersed in this solution, the temperature of this solution was slowly raised to room temperature, and the reaction was allowed to proceed for 7 days. After completion of the reaction, it was washed with methylene chloride and water-acetone to remove by-products and excess P.
BLG was removed. After that, when water was dropped onto the surface of the substrate that had undergone such a reaction, the contact angle was 66 degrees, which was hydrophobic due to the formation of the PBLG monomolecular film.

Then, as shown in FIG. 2, this sample was set on a rotatable sample stage, and laser light having a wavelength of 1064 nm emitted from a YAG laser was made incident on the sample from the monomolecular film side to obtain a laser beam having a wavelength of 532 nm. The second harmonic was detected. The operation was repeated by rotating the sample stage on which the sample was placed. As a result, a remarkable maker fringe pattern in which the SHG intensity increases and decreases depending on the incident angle of the laser beam on the sample is shown. This is PBLG
This is because the dipole moment of is oriented in the direction normal to the substrate. Therefore, it was confirmed that PBLG was oriented on the substrate on which polyvinyl alcohol was formed. [Example 9]

The second harmonic was detected in the same manner as in Example 8 except that PBLG having a molecular weight of 120,000 was used. As a result, a remarkable maker fringe pattern was observed as in Example 8, and the SHG intensity was 4 times that of Example 8. [Example 10]

The sample of Example 8 was treated again with a molecular weight of 51,000.
Was reacted with a methylene chloride solution containing 3 g of PBLG and 0.1 g of DCC for 7 days to form a two-layer film of PBLG. The second harmonic of this sample was detected in the same manner as in Example 8. As a result, a remarkable maker fringe pattern was observed as in Example 8, and the SHG intensity was 3.5 times that of Example 8. [Example 11]

First, a mixed solution of 1 g of tetramethoxysilane (Toshiba Silicone, trade name TSL-8114), 25 g of water, 25 g of acetone, and 1 g of acetic acid was prepared. The tetramethoxysilane concentration in this solution is 1.9 wt%. A contact angle to water is 60 degrees in untreated state A
The l substrate was immersed in this mixed solution and the change in contact angle with time was examined. As a result, the contact angle decreased to 21 degrees in 24 hours.

A mixed solution of 5 g of tetramethoxysilane (Toshiba Silicone, trade name TSL-8114), 25 g of water, 25 g of acetone, and 1 g of acetic acid was prepared. The concentration of tetramethoxysilane in this solution is 8.8 wt%. In the untreated state, the contact angle with water is 78 degrees A
The l substrate was immersed in this mixed solution and the change in contact angle with time was examined. As a result, the contact angle decreased to 24 degrees in 12 hours.

Further, 7 g of tetramethoxysilane (Toshiba Silicone, trade name TSL-8114), 10 g of water,
A mixed solution of 10 g of acetone and 1 g of acetic acid was prepared. The concentration of tetramethoxysilane in this solution is 25 wt%, pH
Is 3. An Al substrate having a contact angle to water of 78 degrees in an untreated state was immersed in this mixed solution, and the change in contact angle with time was examined. As a result, the contact angle decreased to 24 degrees in 6 hours. Thus, with the tetramethoxysilane solution, self-polymerization did not occur even when the concentration was raised to 20 wt% or more, and it was possible to shorten the processing time of the substrate.

Then, a silane coupling agent having an amino group (manufactured by Toshiba Silicone, trade name TSL-8114) 4
g, 200 g of water, and 8 cc of acetic acid were mixed to prepare an aqueous solution of pH 4. Then, the substrate, the surface of which was treated with a solution of tetramethoxysilane having a concentration of 25 wt%, was immersed in this aqueous solution for 12 hours for reaction.

Further, a methylene chloride solution in which 3 g of poly-L-glutamic acid γ-benzyl ester (PBGL) having a molecular weight of 120,000 and 0.08 g of dicyclohexylcarbodiimide (DCC) were dissolved was prepared, and this solution was reacted with the substrate. A PBLG monolayer was formed.

The absorption of the functional group oriented in the direction perpendicular to the substrate was measured by RAS spectrum. As a result, 1
Absorption of carbonyl group was sharply observed at 660 cm ^-1 .

On the other hand, a Si substrate was used instead of the Al substrate, and a PBGL monomolecular film was formed by the same operation as described above. STR polarized light was irradiated to measure the ATR spectrum. As a result, the absorption of the carbonyl group disappeared. From these results, it was confirmed that the PBLG molecules in the PBLG monomolecular film are oriented in the direction perpendicular to the substrate. [Example 12]

A substrate having Cr deposited on glass was prepared as a substrate, ultrasonically cleaned with methylene chloride for 5 minutes, and steam-cleaned with Freon. Further, 2 g of tetraisocyanate silane was mixed with 10 cc of dry methylene chloride and stirred.
The substrate was dipped in this surface treatment solution, allowed to stand for 1 hour, washed with dry methylene chloride and dried.

On the other hand, PB was added to 10 cc of dry methylene chloride.
3 g of LG (manufactured by Sigma, molecular weight 50,000) was dissolved. The surface-treated substrate was submerged in this solution and left to react for 12 hours. After completion of the reaction, it was washed repeatedly with methylene chloride and dried.

When the RAS spectrum of this sample was measured, absorption of carbonyl of ester and amide was observed at 1731, 1650 and 1549 cm ^-1 . When this was compared with the spectrum of the sample in which PBLG was randomly oriented, the peak of carbonyl at 1650 cm ⁻¹ was increased. From this, it was found that the molecular axis of PBLG exists in the direction perpendicular to the substrate, that is, PBLG is oriented in the direction normal to the substrate. [Example 13]

After washing the substrate and treating the surface with tetraisocyanatesilane in the same manner as in Example 12, the reaction with PBLG was repeated to form a PBLG monomolecular cumulative film having a five-layer structure.

The sample shown in FIG.
G was measured. As a result, SHG having an intensity about 20 times that of the untreated glass substrate was observed. From this, it was found that the dipole moment was aligned in the normal direction of the substrate and the orientation of PBLG was controlled. [Example 14]

20 mm × 5 mm prepared glass was prepared as a substrate. The contact angle of this preparation glass with water was 22 degrees. The prepared glass was washed with a stream of distilled water for 1 hour, ultrasonically washed with methylene chloride for 5 minutes, and steam washed with chlorofluorocarbon. A photoresist is applied onto this substrate, exposed, and developed to form a striped resist having a width of 100 μm, a spacing of 100 μm, and 100 cycles on a predetermined region (second region) in a cross section in the longitudinal direction of the slide glass. A pattern was formed.

Further, 25 cc of distilled water and 1 cc of acetic acid were mixed with 1.25 g of a silane coupling agent having an amino group (manufactured by Toshiba Silicone Co., Ltd., trade name TSL-8345) and stirred to prepare a surface treatment solution having a pH of 4. Was prepared. The preparation glass was immersed in this surface treatment solution and the unmasked portion was treated at room temperature for 8 hours. Then, it was washed with acetone, distilled water and acetone in this order and dried.

On the other hand, 3 g of poly-L-glutamic acid γ-benzyl ester (PBLG, manufactured by Sigma) having a molecular weight of 20,000 was dissolved in 50 cc of dry methylene chloride and kept at 0 ° C. to prepare DCC (dicyclohexylcarbodiimide) 1. Four
g for 20 minutes. The preparation glass was immersed in this solution, the temperature of this solution was slowly raised to room temperature, and the reaction was allowed to proceed overnight. After the reaction was completed, the reaction product was washed with acetone and water to remove by-products and excess PBLG. By this reaction, the C-terminal of PBLG binds to the unmasked domain (first region) on the surface of the prepared glass, and a monomolecular film is formed. Next, the resist pattern was removed, and the newly exposed area (second area) on the surface of the preparation glass was treated with a surface treatment liquid containing a silane coupling agent having an isocyanate group (manufactured by Chisso Corporation). Then, the prepared glass was immersed in 50 cc of dry methylene chloride containing 3 g of PBLG having a molecular weight of 20,000 and 1.4 g of DCC, and reacted in the same manner as above. By this reaction, the N-terminal of PBLG binds to the newly exposed domain (second region) on the surface of the prepared glass, and a monomolecular film is formed. As described above, the waveguide having the inverted domain structure made of the PBLG monomolecular film was formed.

The film thickness of the PBLG monomolecular film thus formed is estimated to be about 13 nm when all the molecules are oriented in the direction perpendicular to the substrate surface. This PB
The contact angle of LG monolayer with water is 51 degrees, and PB
It was found to be hydrophobic due to the molecular skeleton of LG. Further, the ratio of carbon to nitrogen on the substrate surface was determined by the XPS method to be about 12: 1. This value is PBL
It is in good agreement with the composition of G.

The second harmonic of this sample was measured with an apparatus as shown in FIG. Prism couplers 33 and 34 are installed at both ends of the monomolecular film 32 on the substrate 31. The positions of the two prism couplers 33 and 34 are set so that the transmission distance of light between them is 15 mm. Light is transmitted in the monomolecular film 32 alternately in two stripe-shaped domains along their width direction. As the incident light 35, the fundamental wave of the Nd-YAG laser (wavelength 1.
064 μm, strength 20 mJ) was used. This incident light was made incident on the monomolecular film from one prism coupler 33 and emitted from the other prism coupler 34. The second harmonic 38 included in the emitted light 36 was separated by the infrared cut filter 37, and the intensity thereof was measured.

As a result, a second harmonic wave of 5 mJ was obtained for an incident light intensity of 20 mJ. This value is very large compared with the intensity of the second harmonic observed in the case of the PBLG monomolecular film having no inversion domain structure, which was 0.1 mJ. [Example 15]

First, a solution of poly-β-benzyl-L-aspartate (PBLA) was prepared according to the preparation of the PBLG solution in Example 14. After this, a step of reacting the C-terminus of PBLA with the N-terminus of the PBLG monolayer in the first region is added, and a step of reacting the N-terminus of PBLA with the C-terminus of the PBLG monolayer in the second region. 2 in the same manner as in Example 14 except that
A waveguide having a layered structure and an inverted domain structure was formed. When the ratio of carbon and nitrogen on the surface was determined by the XPS method, a value that was in good agreement with the composition of PBLA in the upper layer was obtained.

The intensity of the second harmonic of this sample was measured using the apparatus shown in FIG. 4 as in Example 14. As a result, for the incident light intensity of 20 mJ, the second harmonic wave of 7 mJ, which was stronger than that of Example 14, was obtained.

[0096]

As described above in detail, by using the method of the present invention, it is possible to produce a monomolecular film and a monomolecular cumulative film in which the molecules have a strong binding force to the substrate and the molecules are oriented in the same direction.

[Brief description of drawings]

1A to 1C are explanatory views showing the method of the present invention in the order of steps.

FIG. 2 is a configuration diagram of an SHG light measuring device used in an example of the present invention.

FIG. 3 shows SH of a monomolecular cumulative film obtained in an example of the present invention.
The characteristic view which shows G intensity | strength.

FIG. 4 is a configuration diagram of an SHG optical measurement device for a waveguide having an inversion domain structure, which includes the monomolecular film obtained in the example of the present invention as a component.

[Explanation of symbols]

1 ... Substrate, 2 ... Processing layer, 3, 4 ... Molecule, 11 ... YAG laser, 12 ... Prism, 13 ... Photodiode, 1
4, 16 ... Lens, 15 ... Sample stage, 17 ... I
R cut filter, 18 ... Spectrometer, 19 ... Photomultiplier tube, 20 ... Digital oscilloscope, 21 ... Sample, 31
... substrate, 32 ... monomolecular film, 33, 34 ... prism coupler, 35 ... incident light, 36 ... outgoing light, 37 ... infrared cut filter, 38 ... second harmonic.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location C08J 5/18 9267-4F C09D 5/00 PPF 6904-4J 125/18 PFB 9166-4J 129/04 PFL 6904-4J C09K 3/00 C 8517-4H C23C 14/24 7308-4K // C09K 11/00 A 9159-4H (31) Priority claim number Japanese Patent Application No. 3-309249 (32) Priority Date 3 ( 1991) November 25 (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 3-316400 (32) Priority Date 3 (1991) November 29 (33) Priority claim Country Japan (JP)

Claims (4)

[Claims] 1. A step of treating a surface of a substrate to make it reactive, and a molecule having at least one functional group at both ends of a rigid molecular skeleton having a length of 15 angstroms or more is used, and the functional group is added to the substrate. And a step of reacting with the surface of the monolayer. 2. A step of treating a surface of a substrate to give reactivity, and a molecule having two functional groups at both ends of a rigid molecular skeleton having a length of 15 angstroms or more is used. Reacting one with the surface of the substrate
A step of forming a monolayer film of layers and a molecule having two functional groups at both ends of a rigid molecular skeleton having a length of 15 angstroms or more are used, and one of the two functional groups is used as a lower monolayer film. A step of reacting with the other functional group of the constituent molecule to form an upper monolayer film. 3. The method for producing a monomolecular film according to claim 1, wherein at least the surface of the substrate is made of a polymer having a functional group. 4. The method for producing a monomolecular cumulative film according to claim 2, wherein at least the surface of the substrate is made of a polymer having a functional group.